Radiators are among the essential parts of car engines, and any weakness or defect in them can cause severe damage
to the engine. The most critical tasks of radiators is effective heat transfer between air and fluid inside the radiator
tubes, which is done by fans. Since the air temperature has a direct relationship with its pressure, measuring the air
pressure before and after the radiator is necessary. In this research, three different methods have been used to calculate the air pressure drop at speeds of 3, 5, and 8 m/s. The purpose of this work is to introduce the best possible
method to reduce the risks that are caused by the wrong reading of the air pressure drop using the accuracy of the
obtained results, The point that each part of the radiator is determined by which pressure (static or dynamic pressure)
is crucial and plays an essential role for choosing better type of pressure gauge. If this is done, the obtained results
will be correct. If the air pressure drop is not calculated correctly, it can cause severe damage to the engine and other
car parts. The best method that has the slightest error and the least risk for car radiators is when the pressure gauge
calculates the static pressure inside the wind tunnel and the dynamic pressure outside the wind tunnel. In this case,
the error of the obtained results comparing to the standard results is 9.16, 15.41 and 10.18%, at speeds of 3, 5 and 8 .